Fluid lift pump



\ Nov. 19, 1940.. E. w. PATTERSON- FLUID LIFT PUMPy Original Filed April 20, 1938 4 Sheets-Sheet 1 MMM...

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Nov. 19, 1940. E. w. PATE'RsoN 2,222,205

Y vFLUIiJ LIFT PUMP original Filed April 2o, 195e 4 sheets-sheet 2 Nov. 19, 1940. E. w. PATTERsoN 2,222,205

FLUID LIFT PUMP Original Fild April 20, 1938 4 Sheets-Sheet 5 Nov. 19, 1940.

E. W. PATTERSON n FLUID LIFT PUMP original Filed April 2o, 195s 4 Sheets-Sheet 4 m y M fr m Mm VP m wm.

L llllnnunwllllllllll |||\l vIIIlIl Patented Nov. 19,

NITED STATES PATENT 'oi-Fics April 20, 1938. This 1940, Serial No. 325,850

1e claims.

This invention relates to a fluid lift pump especially adapted for use in elevating fluids from oil wells and the like, and is primarily an improvement upon my invention as disclosed in my -United States Letters Patent No. 2,038,441, ,en-

titled Fluid lift pump, issued to me April 12, 1936. The present application is, moreover, filed as a continuation, and in the place and stead, oi' my concurrently abandoned application, illed April 20, 1938, under Serial Number 203,107. and under the same title.

in the operation of oil wells to obtain production of oil therefrom, it is the usual practise to install a plunger pump mechanism within the well in order to elevate the liquid to the surface. Such an installation is quite expensive both in manufacture and use and, under certain conditions, such as when used in a well of great depth, numerous difficulties and problems are encountered, giving rise to serious complications and requiring considerable adjustment and manipulation of parts to obtain an optimum flow of liquid from the well.

In the oil well industry it usually occurs that the oil which is to be drawn from the well is commingled with gas and, while the gas may not be of sufficient pressure to lift the liquid to the surface of the ground, it may be utilized to exert a beneficial pressure which may be built up to overcome the hydrostatic head of the liquid in the well irrespective of the amount of submergence of the lift pump, and this built up pressure may be utilized to lift the liquid from the Well.

It is the principal object of this invention, therefore, to provide a fluid lift apparatus which may be introduced into an oil well to a desired degree of submergence, and which will act to lift the liquid column by means oi.' gas under a pressure substantially less than the normal static L head pressure developed by a solid column of liquid the depth of an average oil well of approximately 4,000 feet developing a static pressure of approximately 1,500 pounds per square inch. Pressures as high as this are commercially impractical in oil Well practise. It will be readily understood, however, that the device as it will be disclosed is equally adaptable for use at shallower depths, as in water raising systems, wherein it can be used in the form of a direct displacement pump motivated by gas under suflicient pressure to overcome the static head pressure developed by the column of Water being raised.

It is a very important object of the invention to provide a fluid lift apparatus of the gas or air motivated type, that will be capable of attaining to actuate the controlling valves.

application March 25,

(Cl. 103--248i a higher degree of efliciency from a power consumption standpoint than that attained by the present systems, by making it possible to supply the maximum quantity of liquid that a given volume of gasV is capable of aerating and propeiling to the surface of the ground or top of the Well.

It will be obvious to those familiar with the art that the device to be disclosed will operate absolutely independent of well pressure, or submergence, and that the motivating gas may be either that developed in the well itself, or supplied from external sources. It will be noted as one of the principal accomplishments of the apparatus that, due to the function of a foot valve, hereinafter described, it is not aifected by the depth to which it is submerged in the liquid of a well, and that operation may be initiated under substantially the same pressure as will be required at any time thereafter. Thus, what is commonly known as high kick over pressure in instances of deep submergence, will not be required.

It is another object ofthe present invention to provide means whereby the fluid under pressure, after having performed useful work in elevating liquid, may be exhausted from the apparatus against a reduced hydrostatic head from that existing at the point where its work was accomplished, whereby maximum pumping efficiency oi' the apparatus may be attained.

It will be apparent from the following disclosure that the device `of' this invention, operating at any depth of submergence Within the liquid of a well, may be efficiently controlled and motivated by iluid under pressure irrespective of the character of the liquid being pumped, and in a manner insuring that the motivating uid will be applied to the liquid to produce-a relatively even velocity flow.

Another object of the invention has to do with the float as used in the present apparatus which, due to the operating pressure and great depths of submergence, must be built to withstand tremendous pressure, necessitating great strength. Since fluids coming into the well are usually of low speciilc gravity, great length must be given to the float to attain sumclent power with which By my structure it will be clearly seen that the oat could be solid and still be given any degree of buoyancy up to its displacement of the uid Within which the apparatus is submerged.

The present invention contemplates the provision of a fluid lift pump mechanism which acts automatically under the influence of a liquid level within the mechanism, and for actuating the iiuid pressure control valves when a minimum or maximum liquid level exists in the apparatus.

The invention is illustrated by way of example in the accompanying drawings, in which,

Figure 1 is a View in central longitudinal section through the lower portion of the main tubing string and the upperportion ofthe fluid lift apparatus, particularly disclosing the gas pressure chamber and a portion of the valve mechanism.

Figure 2 is a view in central longitudinal section similar to Figure 3, showing the partsof the foot valve mechanism as they will appear when the liquid chamber is filled.

Figure 3 is a view in central longitudinal section and elevation, showing` the portion of the fluid lift pump as it occurs at the lower end of the structure and particularly disclosing the details of construction of the foot valve mechanism. It will be understood that Figures 1, 3 and 5 are supplemental to each other and that they indicate the entire iluid lift pump structure with the parts appearing in the relationship as they exist when the main pump chamber is substantially empty.

Figure 4 is a view in central longitudinal section through theportion of the iiuid lift pump mechanism as shown in Figure 1, disclosing the parts in their transposed positions as will occur when the liquid chamber is filled.

Figure 5 is a view in central longitudinal section with parts in elevation, disclosing the adjacent length of the fluid lift apparatus to that shown in Figure l, and further indicating the detalls of construction of the balanced piston, valve and the float control mechanism.

Figure 6 is a view similar to Figure 5, showing the lower parts of the balanced valve and the iloat control mechanism as they will appear when the liquid chamber is filled.

Figure 7 is a view in transverse section through the gas pressure chamber as seen on the line 'I-l of Figure 4.

Figure 8 is aview in transverse ,section as seen on the line 8 8 of Figure 4, showing the various exhaust and pressure passageways in the main valve head.

Figure 9 is a view in transverse through the main valve head as seen line 9 9 of Figure 4.

Figure 10 is a view in transverse through the main valve head as seen line Ill-Ill of Figure 4.

Figure 11 is a view in transverse section through the main valve head as seen on the line II-II of Figure 6.

Figure 12 is a view in transverse section showing the iloat control mechanism as seen on the line I2-I2 of Figure 6.

f Figure 13 is a view in transverse section through the guide structure as seen on the line I3.-I3 of Figure 6.

Figure 14 is a view in transverse section through the foot valve structure as seen on the line III- I4 of Figure 2.

Figure 15 is a view in longitudinal section and elevation, with parts broken away, generally indicating the complete assembly, and further showing means for regulating the jetting elect of the uid under pressure from a point above the ground.

Figure 16 is a view showing the complete assembly.

Figure 17 is a view in transverse section.

section on the section on the through the structure shown in Figure 4, as seen on the line II-II of that gure.

Figure 18 is a view in transverse section through the float structure as seen on the line I8-I8 of Figure 6.

Figure 19 is a fragmentary view in section and elevation showing the retarding and locking structure with its parts in their intermediate position as distinguished from the relation of the parts shown in Figures 5 and 6.

Referring more particularly to the drawings, I0 indicates a well bore which may be tted with a suitable casing II', and through which an exhaust tube I2 mayextend. This tube is substantially concentric with the well casing and is sulciently smaller in diameter to permit the structure to be readily introduced into the accumulated liquid within the well, and to attain a desired degree of submergence. It will be understood, of course, that the exhaust tube I2 is formed in lengths appropriately coupled together to extend from the desired point of pumping operation to a desired point of exhaust which may be above the liquid in the well or at a predetermined level therebeneath.

Mounted upon the lower end of the exhaust tube I2 is a top adaptor shoe I3 to which various parts of the fluid lift apparatus are attached, and by which they are anchored. This adaptor shoe is formed with an upper bore I 4 to receive the threaded end of the tube I2, and a bore of reduced diameter i5 to receive the lower end oi' the main tubing string I6. This string is of considerably smaller outside diameter than the inside diameter of the exhaust tube I2, thus creating a concentric exhaust passageway I1 to accommodate the fluid in a manner to be hereinafter explained.

AThe lower end of the top adaptor shoe I3 is connected with a pipe I8 of approximately its diameter, forming therein a gas pressure and scale trap chamber I9. Gas is admitted to said chamber from the top of the well by way of the annular space between tubing string I6 and a flow string 29 to be presently described. A pressure inlet tube 20 to the main flow chamber 83, to be presently described, is formed with a plurality of perforations 2l through its wall near its upper end, within chamber I9, so that the tube 20 will act as a strainer and prevent extraneous matter from passing from the pressure chamber and scale trap I9 into the pressure control valve, and in this way clogging the apparatus.

The lower end of the gas pressure chamber through which the pressure inlet tube 20 depends. This sub-head has a central passageway 23 extending downwardly through a tubular extension 24 thereof, and terminates at its upper end in a counterbored portion 25 which is threaded to receive the lower end of an aspirator tube 26 extending upwardly into the main tubing string I6 and formed with a. central passageway 21 in communication, and in longitudinal alignment, with the central passageway 23 of the sub-head 22. The aspirator tube 26 is formed at predetermined intervals throughout its length with `jet openings 28 by which fluid under pressure may be admitted into the central passageway 21 thereof in a manner and for a purpose to be hereinafter more fully set forth.

The aspirator tube 26 telescopes into the lower end portion of an adjusting sleeve 29 which has a central bore receiving said tube with a snug the sleeve with relation to the tube any desired number of Jet openings 23 of the latter, may be uncovered and thus a controlled amount of fluid under pressure may be introduced into the column of liquid outiiowing upwardly through the central passageway 21 of the aspirator tube. The sleeve 29 may be adjusted from a point above the surface of the ground in any suitable manner, such ier example as shown in Figure 16 oi' the drawings. s

Secured to the lower 'side of the sub-head 22 is a relatively short casing section 30 which forms therein an exhaust transfer chamber 3l around the tubular extension 24 of the head. The lower end of the casing section 30 is attached to the upper end of a main valve head 32. This valve head is formed with a central liquideduction passageway 33 in longitudinal alignment with the passageways 23 and 21, and in communication therewith and continuation thereof.

Disposed parallel with the passageway 33 in the valve head 32, and extending through this head, is a cylindrical bore 34 which receives a balanced piston valve 35. The valve 35 may reciprocate longitudinally within the bore 34 and will act to control the inlet of pressure gas or air to force eduction of liquid from the fluid lift chamber, and the exhaust of spent pressure therefrom to permit refilling of the fluid lift chamber from the well.

The valve 35 comprises two cylindrical portions, an upper portion indicated at 36, and a lower portion indicated at 31. 'I'hese portions 36 and 3l are connected by a stem 33 of considerably smaller diameter, forming therewlthin a by-pass passageway to permit-communication between certain bores of. the valve head when the piston valve. 35 is reciprocated from one extreme position to the other. The upper end of the bore 34 for the valve 35 is closed by a plug 39.

Formed at diametrically opposite sides of the valve head 32, as indicated in Figure 8 of the drawings, is a pair of exhaust passageways 40 and 4|, which extend longitudinally of the valve head and parallel to the axis thereof. 'I'he upper ends of these exhaust passageways communicate with the exhaust transfer chamber 3|, which latter is open at its upper portion to the lower ends of a plurality of exhaust transfer tubes 42. These tubes 43 extend upwardly through the sub-head 22 and pressure chamber I9, and communicate at their upper ends with passageways 43 through adaptor shoe i3, which passageways 43 are in communication at their upper ends with the exhaust space i1 formed between the exhaust tube l2 and the main tubing string I6. The exhaust passageways 40 and 4I do not extend downwardly throughout the entire length of the head 32, but terminate at their lower ends at a point short thereof to communicate with laterally extending exhaust ports 44 which extend to and communicate with, the valve bore 34 as seen in Figure 11.

Extending upwardly from the lower end of the main valve head 32 is a pair of pressure passageways t and 46 as seen in Figures 9 and 10, which passageways terminate short .of the upper end of the head and open at their upper ends into laterally extending chamber port 41 intermediate the upper and lower ends of the head. This port 41 communicates with the valve bore 34L and, when the valve 35 is in its lower position indicated in Figure l, the shoulder at the upper end of the portion 31 of the valve will register with the lower edge oi chamber port 41, and the spindle portion 33 of the valve will form a passageway 43 within the bore 34 to permit the pressure fluid to communicate with the pressure port 50 formed in the valve head 32, the latter port 50 being in gimmunication with the pressure chamber tube It will be noted from the drawings that the.

exhaust ports 44 are disposed at points below the chamber port 41, and that the space between the portions 33 and 31 of the valve 35, as defined by the length of the spindle 33, is such as to 'insure that the chamber port 41 may be either in communication with the exhaust ports `44 or with the pressure port 50.

The valve 35 is formed with acentral bypass duct 52, which tends to break the seal that might otherwise occur between the upper end of the valve and theupper closed end of its cylinder. By this duct 52 I provide for equal hydrostatic pressure at opposite ends of the valve so that the valve will be balanced and can move without the resistance of any hydrostatic head or pressure which might occur at either end of the valve, or through the valve head ports.

The valve 35 is provided at its lowerend with a valve stem 53, shown particularly in Figures 5 and 6. This stem is actuated by a mechanism which will now be described. Mounted at the lower end oi the valve head 32 is an eduction tube nipple 54, which is formed with a central tubular opening communicating, and in alignment, with the central eduction passageway., through the valve head. 'I'he nipple 54 is formed on the upper end of an eduction tube valve housing 55 which is tubular in shape and extends downwardly to house a valve seat 56 for a ball valve 51 in the eduction bore 58. The lower open end of the valve housing 55 receives the threaded upper end oi a friction mandrel 53', and the lower end of this mandrel, as best seen in Figure 6, is threaded to receive the upper threaded end of the eduction tube section 59. This tube section 59 depends freely through the sleeve 50 which telescopes over the friction mandrel 58. and said sleeve is thus free to reciprocate with respect to, and around, the eduction tube section 59 for a purpose which will hereinafter more fully appear.

Upon the sleeve 30 are formed lugs 6l which receive pivot pins 32. These lugs and pins pivotally support friction arms 63 so that their free ends extend upwardly along diametrically opposite sides of the sleeve 60 for the support of friction rollers 54 at said free ends. These rollers extend inwardly through slotted openings 65 in the opposite sides of the sleeve 50, so, that the rollers may be held in yieldable contact with the surface of the mandrel 58 by means of springs 65.

The mandrel 58', as best shown in Figures 5, 6 and 19 of the drawings, is formed at a point in its length with a circumferential shoulder 61 which has an upper inclined face 68, a lower and oppositely inclined face 69, and an intermediate cylindrical fiat face 10. The arrangement is such that when the sleeve is in its lower position the rollers 64 will be below the shoulder 61 and in, contact with the lower inclined face 69. When the sleeve 33 is at an intermediate position and is moving upwardly or downwardly, the rollers will freely roll against the flat face 10, and when the sleeve 60 is in its uppermost position the rollers 64 will be above the shoulder 61 and in contact with the upper inclined face $8, as best seen in Figure 6. The intermediate position of the sleeve is indicated in Figure 19.

It will be evident that by properly selecting a' rigidly mounted.

desired angle of inclination for the faces 69 and 69, and a desired'tensicn for the springs 69, it will be possible to impose a predetermined frictional load upon the sleeve 60 which must be overcome before the sleeve will move vertically from one extreme position to the other with respect to the mandrel 56'.

'I'he upper end of the sleeve 60 is formed with an annular collar 1| which engages a groove 12 in the side of the valve stem 53, which groove as here defined is of a width sumtantially twice the width of the annular collar 1I, thus permitting limited relative longitudinal movement of the sleeve 80 with respect to the valve stem 63, while maintaining their operative relation.

Mounted within the valve housing 55, and seating upon the valve seat 66 is the ball valve51 previously mentioned, upward movement of which valve is limited by a pin 51'. Connected to the lower end oi' the sleeve 60, as seen in Figure 6, is a float tube 14 upon which a float 15 is It is to be understood that there may be a plurality of float elements 15 in rigid connection depending upon the deadweight and the buoyant weight of the floats required in producing the desired action in response to the buoyant effect produced by the liquids which accumulate within the float or liquid chamber 83 as presently described.

Mounted at the lower end of the float or floats is a tubular fitting 16 which has la central I threaded bore to receive the lower threaded end plurality of ports 11 in its wall which afford communication between the lower open end of the eduction' tube 59 and the previously mentioned liquid chamber 83 formed within a cylindrical casing 88, whose upper end is rigidly in threaded connection with the lower end of the valve head 32. The lower end of the extension 16 is closed and is threaded into'the upper end of a guide fitting 84, so that this fitting is in rigid connection with the sleeve 60, through the float 15 and float tube 14, and these parts thus operatel as a unit.

The guide fitting 84 at the lower end of the above mentioned unit, and the sleeve 60 at the upper end thereof, are formed with a plurality of lugs 85, as best seen in Figures 13 and 14. These lugs 85 receive pins 86 which carry guide rollers 81 in an arrangement therearound radially with respect thereto so that their disposal adapts them to bear against the inner surface of the cylindrical wall of casing 88; above described as enclosing the float 15 and forming therein the liquid chamber 83.

The guide fitting 84 is also formed with a central bore 89, which is of a .predetermined and substantial length and is closed at its upper end by the threaded lower end of the extension 16. At the lower end of the bore 89, the fitting 84 has an end Wall 80, through which an opening 9| extends to receive vthe upper end of a valve stem 92. A nut 93 is threaded onto this valve stem within bore 89 and thus the valve stem has a limited movement relative to the fitting 84, between the lower wall 90 thereof, and the lower end of the extension 16.

The valve stem 92 reciprocates through a stuffing box 95 in the upper end of a valve cage 96. This cage is formed with an upper valve seat 91 and a lower valve seat 98, which are preferably arranged so that the tandem valve, as presently described to seat thereon, will be substantially neutral in either open or closed position. 'I'he valve stem 92 is fitted at its lower end with a hollow threaded boss 99, which receives the threaded extension of a tubular valve stem 00, carrying a lower valve member of the tappet type, at its lower end.

A by-pass duct |02 is formed axially through the valve member |0| and its stern |00, and communicates with a chamber |03 in the valve cage 96 above a tappet valve |04 mounted on the upper end of the stem |00. The hollow boss 99 is formed with lateral openings which establish the central duct |02 incommunication with the chamber |03, to thus provide said chamber with liquid at the pressure existing in the well below the valve member |0| so that the valve may be partially or wholly balanced. The lower end of the valve cage 96 is formed with side wall outlet ducts |05, located above the valve member |0| and opening into the liquid chamber 83. Clearance ports |06 are also formed through the wall of the valve cage below the valve member |04 and above a valve guide |01.

Within the lower portion of the casing 88, a compression coil spring |08 seats at its lower end upon the shoulder of a foot valve extension |09, and bears at its upper end against a flange on the lower end of the guide fitting 84 to exert a force tending to move the float assembly in an upward direction. The foot valve extension |09 is threaded into the lower end of the casing 88 and anchors the valve cage 96, and said exteny sion is also formed with a valve seat ||0 therein,

receiving a foot valve ball upward movement of which ball is limited by a transversely extending pin ||2. A flow tube extension |I3 is threaded to, and extends downwardly from, the fitting, |09, and may receive a perforated pipe or nipple .I I4, as seen in Figure 16.

Whenthe float 15, float tube 14, sleeve 60, guide fitting 84, and associated parts, which, in their unitary assembly constitute a displacement member, are in the position indicated by the position of the valves in Figure 2, it will be evident that the buoyant action of the oat and the expansive action of the spring |98 are combining to maintain the displacement member in its upper position. In such position the tandem valves 0| and |04 will be positively held upon their seats.

'I'he displacement member, including float 15, is designed to respond to the level of liquid within liquid chamber 83, which chamber is provided by the confined space within the casing 88 for its full length between the fluid valve head 32 and the foot valve extension |09. Due to the fact that conditions of excess pressure will prevail within the main liquid chamber 83, the float 15 may be given additional weight and strength, and in any event its degree of buoyancy may be definitely controlled in a manner and for purposes to be hereinafter set forth.

The selection of the spring |08 for the purpose of pumping a particular well is of great importance due to the fact that the pumping action may be carried on at any desired depthof submergence, and the fact that the specific gravity cf the liquid to be pumped may ,be reduced by aeration of the liquid by the gas present in the 'tibi well or introduced by the supplied fluid pressure for the operation of the pump.

The degree oi buoyancy of the float structure must be accurately controlled; for example, assuming that the weight of the oat when dry is 250 pounds and that its weight when submerged in theparticular liquid to be pumped is 200 pounds, there would be a iiuid displacement of pounds. Under such conditions is might be desirable to provide a spring |06 having a tension of 225 pounds so that when the float is dry or unsubmerged the weight of the float would over-balance the strength of the spring by 25 pounds, and when the iioat is submerged the spring would give the float a buoyancy of 25 pounds. This differential may be further adjusted for accuracy by the tension imposed upon springs 66 carried by roller arms 63 on the sleeve 66. This will make it possible to control the force with which the rollers 64 bear against the faces of collar 61, which force must be overcome by the buoyant action or weight 'of the iioat in its vertical reciprocating movements.

. In operation of the present invention, the lift mechanism is mounted at the lower end of the exhaust tube I2, and is also connected to the main tubing string I6. Extending downwardly through this tubing string from a point above the ground is the flow tube 26 which cooperates with the aspirator tube 26 to regulate the effective area provided by the uncovered perforations 28 in the aspirator tube. Before the structure is lowered into the well the depth of submergence at which the device is to operate will have been determined, and in addition thereto a sample of the fluid to be lifted will have been taken at the determined operating depth so that the specific gravity of the liquid will be known.

The weight of the float structure 'l5 is then ascertained and the required buoyancy of the float when submerged is calculated. A spring Hi8 is selected to meet the requirements indicated by the conditions in the well. The assembled structure is then lowered into the well to the previously determined depth of submergence. lt will be understood that the greater the depth of submergence within the liquid of the well the greater will be the hydrostatic head of liquid acting upon the apparatus. It will also be assumed that when the device is initially set in operation the main chamber' will be without liquid therein and that the foot valve extension ldd is submerged in the liquid which has lifted the foot valve lil and tends therefore to flll the central passageway i60 of the tandem liquid valve and to flow into the main chamber Si. At this time the parts are in the position shown in Figure 3, and the float structure 'i6 rests on the spring ldd, upward movement of said structure being resisted by the friction exerted by the rollers 6d against the shoulder 6a of the collar 6l.

When suflicient liquid has entered the chamber di, with the displacement member in its lower position of rest, and the tandem valve open as above, to promote a buoyancy overcoming the resistance to its upward movement by the rollers bil of the friction mandrel assembly, the displacement member moves suddenly from its lower position of rest to its upper position of rest as seen in Figures 2, 4 and 6, thereby causing the balanced tandem valve to close as in Figure 2, and effectively prevent any further liquid entering chamber 83 from the w-ell, whether or not gas pressure has been admitted into the upper portion vof said chamber. l

Thus it is plain that the primary purpose of the friction mandrel assembly is to resist movement of the displacement member until such time as there. has been suiiicient buoyancy or weight developed to insure complete movement of said member from one position of rest to the other without danger of stopping between such positions.

In view o1' the fact that the springs 66 in connection with the retarding rollers 64 of the friction mandrel assembly havebeen selected with a predetermined strength so as to provide definite resistance to the movement of the displacement member, a predetermined buoyant action must `be accumulated for the iioat structure to rise. This buoyant action must be suilicient, with the help of the spring |08, to separate the rollers 64 and to force these rollers upwardly over the inclined shoulder 69 of collar 61, to the position indicated in Figure 6, which brings the lower guide extension 84 to the position indicated in Figure 2.

It will be evident that when the float structure moves to its upper position of rest, the tandem valve will be shifted upwardly until the valve .members thereof fully seat. Prior to this seating it will be understood that liquid has been freely iiowing upwardly through the pipe H3, past the lifted valve ball lli and the lower end of the tandem valve, into the chamber 83 through the ports |05.

When the tandem valve lili has been completely seated, the upward flow of liquid into chamber 83 will definitely cease, and this will prevent the filling of the entire apparatus to the level of the liquid in the well, which would otherwise occur.

Prior to any upward movement of the displacement member or float assembly and until its force overcomes the tension of the springs 66 so that the rollers 64 may pass over the shoulder 69 of collar 6l, it will be understood that the valve stem 53 and the piston valve 35, will be in its lowermost position and that a portion of this valve around its spindle 36, as shown in Figures l and 5 will permit communication between the main fiuid chamber and the exhaust tube i2 and main tubing i6 by way of the tubes 42, exhaust transfer chamber di, passageways d0, fil, valve passageway 49, and passageways d5 and 46, which latter passageways communicate with the main liquid chamber d3. With the piston valve in this position it is evident that the chamber may fill with liquid readily under a pressure equal to that prevailingV in the exhaust passageway l'l.

When the sleeve 66 has beenmoved to its uppermost position, as indicated in Figure 6, the shoulder 'li will have engaged the shoulder at the upper end of groove 'l2 of the valve stem lid to move the pistonvalve 36 instantly toitsv uppermost position. At this time the piston valve will be shifted from the position indicated in Figure l to the position indicated in Figure 1i. This will cause the ports dl to be placed in communication with the pressure port bil and, since the chamber port is in communication with the pressure passageways d5 and 46, the fluid under pressure within the pressure chamber i9 ano the gas pressure area between the inside of the main tubing string I6 and outside of the aspirator the space above the liquid in chamber 83.

G in the chamber.

So long as there isa slight differential in pressure between that admitted to the main liquid chamber 83 and that constantly prevailing inside the aspirator tube and ow column, and since Well pressure is now cut oil', it is evident that pressure within the chamber 83 above the liquid will force such liquid up through the eduction tube through suitable ports and will be assisted in this action by the constantly delivered incom- 10 ing gas which passes directly into the aspirato tube.

When the liquid in chamber 88 has been forced through the ports or ducts Tl and into the'eduction pipe 59 to a suicient extent the float 15 will l5 drop within the chamber 83 until the end 94 of the extension 16 strikes the end of the valve stem extension 92, and as the iioat continues to lower due to its weight and lack of buoyancy, it will impose its weight upon the end of the said valve 20 stem until it overcomes the pressure of the liquid acting against the lower face of the valve member 58| of the tandem valve. In so doing it also overcomes the friction exerted by the collar 5l and forces the rollers 64 apart against the tension of springs 66 in riding said rollers over the upper inclined shoulder 68 of said collar 61. In this way the entire float assembly or displacement member moves downwardly from the position shown in Figure 6, through the intermediate position shown in Figure 19, to the position shown in Figure 5.

Thus as the liquid level in the chamber 83 is lowered to a predetermined level, the oat will also lower, although the lower tandem liquid valve will not be again opened until the end face of extension 16 actually engages the upper end of the valve stem 92. f

It will be evident that, due to the lost motion occurring between the end of the tandem valve stem 92 and the face 94, when the weight of the float causes it to strike the valve stem, there will be a tendency for it to jar the valve structure open and readily break the seal. The weight of the oat will then hold `the tandem valve open, as before explained, and this will arrange the parts of the mechanism and prepare the structure for a new cycle of operation in which the chamber 83 will begin to ll with well liquid.

From the foregoing it will be apparent that in so far as the normal cycle of operation is concerned, the balanced valve assembly performs no function other than that which an ordinary ball foot valve Ill would perform. Theoretically at least, the balanced valve assembly could be entirely eliminated, as foot valve Ill will admit G5 both inside and outside of the pumping device at the time it is lowered into the well, or at any time |thereafter that it may be necessary or desirable to release all the gas pressure from the device. 'Ihe advantage of the balanced valve is that it 70 eliminates the necessity for the common high kick over pressure met with in all flowing devices that are initially submerged to any appreciable depth in liquid. It lends to the present device the characteristic of normal initial operating 7B pressure.

It is plain, then, that the balanced valve assembly is not essential to the present invention, and that if it is used, the ball foot valve lll can be eliminated. On the other hand if the balanced valve assembly is not used, the foot valve III, or its equivalent must be present.

When the pressure of the hydrostatic head of liquid within the liquid chamber 83 and the fiuid pressure therein has been spent, the eduction valve ball 5l will seat and will cause a column of liquid to be entrapped in the eduction passageway above said valve. 'Ihe height of this column of liquid will be in direct ratio to the quantity of liquid which has been impounded within the main chamber 83. When the liquid level within the main chamber 83 lowers, the oat 15 will consequently lower until a sufficient amount of its weight has been imposed upon the valve stem 92, as previously described.

Attention is directed to the fact that the column of liquid passing through the aspirator tube 28 will be aerated by the fluid admitted through the passageways 28 in the wall of the tube, and that by regulation of the aspirator sleeve 29, the amount of fluid required for this purpose may be accurately controlled so that the fluid will not blow through the column of liquid but will act to lighten the column of liquid as Well as to elevate it, thus creating a true fluid lift operation which is at all times within the control of the operator above ground.

Since the pumping apparatus of this invention operates within a column of liquid whose height may vary considerably, and may extend for varying distances above the apparatus, it is recognized that the pressure head will vary in proportion to such height. Furthermore, since the exhaust pressure of the fluid passing upwardly through the pump and through the exhaust tube l2 will be limited in pressure, it will be necessary to extend the exhaust tube l5 upwardly through the column of liquid within the well to a point above the liquid level. Thus it will be evident that in different wells the pipe I5 will be of different lengths.

It will also be. evident that although excessive pressures occur upon various opposed surfaces of the piston valve 35, the bypass duct 52 thereof will insure the breaking of any seal between the opposite ends of the valve member, and will balance the pressure so that the piston valve may operate with the same freedom as though it were moving in conditions of uniform atmospheric pressure.

Plainly, the apparatus here disclosed provides simple and elective means for lifting and expelling liquid from oil or water wells, while utilizing the beneiicial forces produced by the hydrostatic head of the liquid Within which the device is submerged, and the gas pressure which may occur in the well. Plainly, also, the device may be controlled and adjusted from a point above the ground to insure that it will operate efciently under conditions as they may uniformly occur ina well, or to meet emergencies arising from varying conditions created by changes in the ow of the well and differences in gas pressure.

While I have shown the preferred form of my invention, as now known to me, it will be understood that various changes may be made in combination, construction and arrangement of parts by those skilled in the art, without departing from the spirit of the invention as claimed.

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Having thus fully described my invention, what I claim is:

1. A fluid lift pump structure comprising a fluid lift pump adapted to be positioned in a well at a predetermined degree of submergence, a main chamber within said pump and into the bottom of which fluid may flow from the well, a ow conduit leading from the main chamber to the top of the well, a pressure conduit for delivering uid under pressure from the top of the well to the main chamber, valve means within the pump structure for establishing and interrupting fluid flow from the pressure conduit to said chamber, valve means at the lower end of the main chamber acting to establish and interrupt flow of liquid from the well into the said main chamber and balanced by the liquid in a manner to maintain itself in full open and closed positions, a float operatively connected with both of said valve means for alternately opening and closing the same,`and,yieldable means resisting movement of said float toward a position to open the lower valve means.

2. A fluid lift pump structure comprising a fluid lift pump adapted to be positioned in a well at a predetermined degree of submergence, a main chamber within said lluid lift pump and into the bottom of which liquid from the well may iiow, a flow conduit leading from the main chamber to the top of the well, a pressure conduit for delivering fluid under pressure from the top of the well to the main chamber, valve means within the pump structure for establishing and interrupting fluidy flow from the pressure conduit to said chamber, valve means at the lower end of the main chamber acting to establish and interrupt flow of liquid from the well into said main chamber, said valve means being pressure balanced in a manner to be neutral in open and closed positions, a float operatively connected with both of said valve means for giving them impulses to alternately open and close, yieldable means resisting movement ci' said float toward a position to open the lower valve, and means acting to resist movement ol the float in its up and down directions until predetermined buoyant values have been reached within the main chamber.

3. A fluid lift pump structure comprising a fluid liit pump adapted to be positioned in a well at a predetermined degree of submergence, a main chamber within said pump and into which liquid from the well may flow, valve means exposed to liquid pressure within a well and balanced thereby for positively admitting and excluding flow of liquid from the well into the main chamber, a float structure opening and closing said valve means and being subject to the buoyant action of liquid in said main chamber, means for delivering huid under pressure to the main chamber, a conduit connected with the pump structure and upwardly through which liquid from the main chamber may pass, valve means for controlling the flow of fluid under pressure through said delivery means, into said main chamber, means operatively connected with said float structure for actuating said fluid pressure valve means, and spring means directly and yieldably supporting the iioat structure and tending normally to hold the liquid valve in closed position.

d. A. fluid lift pump structure comprising a fluid litt pump adapted to be positioned at a deter-A mined degree of submergence, a main chamber within said pump and into which liquid from a well may freely flow, valve means exposed to liquid pressure of a Well and balanced thereby for positively admitting and excluding now of liquid from the weil into the main chamber, a float structure opening and closing said valve means and being subject to the buoyant action of liquid in said main chamber, means for delivering fluid under pressure to the main chamber, a conduit connected with the pump structure and upwardly through which liquid from thepump may pass, valve means for controlling the flow of fluid under pressure through said delivery means, into said main chamber, means operatively connecting said iloat structure with said fluid pressure valve means for actuating the latter, spring means directly and yieldably supporting the float structure and tending normally to hold the liquid inlet valve closed, and yieldable means resisting movement of the float in either direction and to release the float for movement when a predetermined condition of buoyancy has been created within the main chamber.

5. A fluid lift pump adapted to be submerged to a predetermined level in the liquid of a well. com.. prising a tubular pump housing, a tubular con duit connected to the upper end of said housing whereby liquid from the well may flow directly up,

through the housing and the conduit, a pressure chamber within the housing adjacent to the upper end thereof, a liquid chamber within the lower end of the housing, the liquid conduit continu- .ing downwardly through the pressure chamber and the liquid chamber and terminating adjacent the lower end of the liquid chamber, a check valve at a point in the length of said conduit to prevent flow of pressure fluid through said conduit from the pressure chamber into the liquid chamber, a valve structure within the liquid chamber and at the lower end oi the conduit therein and including a liquid-balanced valve member for preventing flow of liquid from the well into the liquid chamber and the conduit when the valve is closed, a float structure within the liquid chamber and operatively connected with the valve structure for controlling the same, and yieldable means partially supporting the weight of the float structure and assisting in holding the oat structure in its upper position for maintaining the balanced valve in closed position.

6. In a fluid lift pump structure adapted to be positioned in a well at a predetermined degree of submergence, means forming a main chamn ber having an opening for the reception of lquid from a well, a valve mechanism controlling said opening and exposed to, and balanced by, the liquid of the well l'or establishing and interrupting flow of liquid from the well into the said main chamber, a flow conduit leading from the main chamber to the top ci the well, a pressure conduit for delivering fluid under pressure from the top of the well to the main chamber, valve means adjacent tothe main chamber for establishing and interrupting fluid flow from the pressure conduit to said chamber and the exhaust of fluid pressure from the chamber, a float movable in the chamber, and operative connections between the float and both valves for alternately vopening and closing the latter, including means effective to kiclr the balanced valve into closed and open positions when the float reaches the limit oi its up and down movements.

7. In a fluid lift pump structure adapted to be positioned in a well at a pre-determined degree of submergence, means forming a main chamber into which liquid from the well may flow. a ow conduit leading upwardly from the main chamber to the top of the well for the discharge of liquid from said chamber, a pressure conduit for delivering fluid under pressure to the main chamber, valve means for establishing and interrupting the flow of fluid from said pressure conduit to said chamber, a valve exposed to and held in open and closed positions by the liquid of the Well, for establishing and interrupting flow of liquid from the well into the said chamber, a float movable in the main chamber, and operative connections between the float and both said pressure and liquid valves for alternately opening and closing the latter, said float having a limited movement with respect to both valves, and said connections including means effective to kick the said balanced valve into closed and open positions when the float respectively reaches the limits of its up and down movements.

8. In a fluid lift pumpstructure adapted to be positioned in a well ata pre-determined degree of submergence, means forming a main chamber for the reception of liquid from the Well, a ow conduit leading upwardly from the main chamber for the discharge of liquid therefrom, conduits for the delivery of fluid under pressure to the main chamber and its exhaust therefrom, a pair of normally balanced valves, one controlling the flow of fluid pressure to, and its exhaust from, the main chamber, and the other establishing and interrupting inflow of liquid from the well to said chamber, a oat operating in the chamber and having limited movement in relation to both of said balanced valves, and connections actuated by the float for positively shifting said valves from one position to another as the float reaches the end of its travel in each direction.

9. In a fluid lift pump of the character described, including a main chamber, a Valve assembly adjacent the upper end of said chamber including a valve for controlling the flow of a pressure fluid downwardly into the chamber, means forming an outflow liquid line including a bore through said assembly and an eduction tube rigidly depending therefrom into the chamber, valve means at the lower end of the chamber exposed to, and balanced by, liquid pressure within the well, for positively admitting and excluding the flow of liquid from the well into the main chamber, a displacement member slidable vertically around the eduction tube asa unit, including a float structure, an upper member having a movable connection with the uid valve and a lower member having a movable controlling connection with the liquid-balanced valve, friction means between said displacement member and a portion of the eduction tube for retarding up and down movements of the former, and a spring in the lower portion of the main chamber partially supporting the weight of the displacement member when the ma'm chamber is free of liquid.

10. In a fluid lift pump for Wells, including a cylinder forming therein a main chamber, valved means at the upper end of the chamber controlling the inlet of fluid under pressure, a valve controlling the inlet of liquid from the well into the lower portion of the chamber and including liquid-balanced means normally holding the valve in closed position, a stationary eduction tube opening downwardly into the chamber axially of the latter, a displacement member movable vertically around the eduction tube and in a single unit including a oat structure and having an upper movable controlling connection with the fluid valve and a lower movable controlling connection with the liquid valve, a spring within the lower portion of the chamber for supporting a portion of the weight of the displacement member, and friction means for normally retarding upward and downward movements of the displacement member.

11. In a fluid lift pump for wells, including a cylinder forming therein a main chamber, valved means at the upper end of the chamber controlling the inlet of fluid under pressure, a valve controlling the inlet of liquid from the well into the lower portion of the chamber and including liquid-balanced means normally holding the valve in closed position, a stationary eduction tube opening downwardly into the chamber axially of the latter, a displacement member movable vertically around the tube and in a single unit including a float structure and having an upper movable controlling connection with the uid valve and a lower movable controlling connection with the liquid valve, a spring within the chamber supporting a portion of the weight of the displacement member, said eduction tube having an annular enlargement with upper and lower inclined faces, and said displacement member having slotted openings in a portion thereof opposite to said enlargement, and spring controlled friction members carried by said displacement member and engaging the enlargement of the eduction tube through said slotted openings.

l2. In a fluid lift pump for wells, including a cylinder forming therein a main chamber, valved means at the upper end of the chamber controlling the inlet of uid under pressure, a valveI controlling the inlet of liquid from the well into the lower portion of the chamber and including liquid balanced means rendering the valve substantially neutral to all pressures, a stationary eduction tube opening downwardly into the chamber axially of the latter, a displacement member movable vertically around the said tube and in a single unit including a float structure and having an upper movable controlling connection with the fluid valve and a lower movable controlling connection with the liquid valve, a spring supporting a portion of the weight of the displacement member, friction means for normally retarding upward and downward movements of lthe displacement member, and roller guide means carried by the displacement member at vertically spaced points thereon and engaging the inner surface of the cylinder for guiding the said member in its movements and spacing the same from the cylinder and the eduction tube.

13. In a uid lift pump for Wells, including a cylinder forming therein a main chamber and having a iluid pressure inlet at the upper portion of said chamber, and a liquid inlet at the lower portion thereof, valves controlling said inlets, an eduction tube stationarily depending within, and opening at its lower end into, the lower portion of the chamber, a displacement member movable vertically in the chamber as a unit around and below the eduction tube and including a float assembly and upper and lower portions fixed in connection with said float assembly and respectively in movable controlling connection with the fluid and liquid valves, friction means for retarding upward and downward movements of the displacement member, a spring in the chamber supporting a portion-of the weight of the displacement member and engaging the same at all.

times, and movable guide means for holding the 14. A iiuid lift pump structure adapted to ber positioned in a well at a. pre-determined degree of submergence, comprising means forming a main chamber therein, into the lower portion of which chamber liquid from the well may flow, an outflow conduit for the liquid leading to the top oi' the well and including a stationary eduction tube axially of the main chamber and opening therein, a pressure conduit for delivering fluid under pressure from the top or the well to the main chamber, valve means for establishing and interrupting fluid flow from said pressure conduit to said main chamber, valve means to establish and interrupt flow of liquid into the lower portion of the main chamber from the well and including a liquid-balanced valve member, a dis-v placement member movable vertically in guided relation within the main chamber around and below the eductiontube and in a single unit including a float structure and means above and below said float structure operatively connected respectively .to said fluid and liquid valves for impelling the latter to alternately open and close, a spring in the main chamber and engaging and supporting a portion of the weight of the displacement member, and means carried by and movable with the displacement member to resist its up and down movements until pre-determined buoyant and weight values thereof have been established within the main chamber.

15. In a fluid lift p-ump for wells, means forming therein a main chamber having an upper placement member, and a spring in the chamber engaging the displacement member at all times and supporting a portion of the weight of said member.

16. In a fluid lift pump for wells, means forming therein a main chamber, valved means controlling the inlet of fluid pressure into the upper portion of said chamber and its exhaust therefrom, a valve controlling the inlet of liquid into the lower portion o! the chamber, a flow conduit for the discharge of liquid from said chamber including a stationary eduction tube opening at its lower portion into the lower portion of the chamber, a displacement member movable vertically in guided relation to the eduction tube within the chamber, including a float structure and having fixed to said float structure an upper operative connection with, and controlling, the fluid pressure inlet and exhaust valve means, a spring within the chamber in engagement with said displacement member at all times and supporting a portion of the weight of the said member, and friction means for normally retarding vertical movements of the said displacement member.

17. In avfluid lift pump for wells, a cylinder forming therein a. main lift chamber, valved means at the upper end of the chamber controlling the inlet of fluid under pressure, a valve controlling the inlet of liquid from the well into the lower portion of the chamber and including liquid balanced means rendering the valve substantially neutral in open and closed positions, a stationary eduction tube extending downwardly into the chamber and opening at its lower end axially of the lower portion of the chamber. a displacement member movable vertically around the tube and in a single unit including a float structure and having fixed to said float structure an upper movable controlling connection with the iiuid valve and a lower movable controlling connection with the liquid valve, and a spring within the chamber supporting a portion of the weight of the displacement member and engaging the same at all times.

18. In a fluid lift pump for a well, means forming a main liquid displacement chamber, fluid pressure supply means for said chamber, fluid pressure exhaust means for said chamber opening into the well at a point substantially above the said main chamber, valve means controlling the inlet of pressure to said'chamber from said supply means and its exhaust therefrom through said exhaust means, a valve controlling the inlet of liquid into the chamber from the well, a flow conduit -for the discharge of liquid from said chamber including a stationary eduction tube depending within, and opening at its lower portion into the lower portion of, the chamber, a displacement member movable vertically in guided relation to the eduction tube within the chamber, including a float structure and having fixedto said iioat structure an upper operative connection with, and controlling, the fluid pressure inlet and exhaust valve means, said displacement member being in a single unit, a spring within the chamber in engagement with said displacement member-at all times and supporting a portion of the weight of the said member, and friction means for normally retarding vertical movements of the said displacement member.

19. In a uid lift pump for wells, a cylinder forming therein a main lift chamber, valve means controlling the inlet of fluid pressure to said chamberand its exhaust therefrom, a stationary eduction tube opening downwardly into the chamber, a displacement member movable vertically in the chamber in guided relation to the eduction tube and in a single unit including a float structure and having a movable controlling connection with the fluid inlet and exhaust valve means, a valve controlling the inlet of liquid from the well into the said chamber and including liquid balanced means rendering the valve substantially neutral in open and closed positions, operative connections between the displacement member and said liquid valve for controlling the latter and acting to limit the upward buoyant movements of the displacement member, and a spring within the chamber supporting a portion of the weight of the displacement member at all times.

EDGAR W. PATI'ERSQN. 

